Overland Travelers who visited Utah Mormons were horrified, fascinated and bemused by plural marriage.
One of the most unique aspects of LDS history is the period when the Mormons practiced polygamy. Historian Kathryn Daynes has found that in the initial years of settlement in Utah, at least 36.9 percent of women who married in Utah became plural wives. Virtually all Mormon leaders were polygamous, increasing the practice’s visibility. Plural marriage certainly created a huge psychological divide between Mormons and the rest of the world, which was felt by non-Mormon visitors to the Salt Lake Valley before polygamy was abandoned in 1890. Non-Mormons were variously curious about, appalled by and amused by plural marriage.
Polygamy was such a radical departure from the traditional American family, that most travelers were intensely curious about it. Mark Twain visited Salt Lake City in 1861 and later wrote about looking forward to making “the customary inquiries into the workings of polygamy.” Apparently everyone asked about how polygamy worked. Richard Ackley spent a year and a half in Salt Lake City and asked many women about the institution. “I have had women talk to me by the hour about polygamy, endorsing it in every way, and it is useless for any one to undertake to argue with them on the subject…because they are so well posted in scripture that they can quote it almost from beginning to the end.” It seems that Ackley tried to argue the point with the Mormon women, but failed.
Many of the witnesses of polygamy were understandably appalled by the practice. There seem to be two main causes. Polygamy seemed to outsiders to break up the normal family and seemed to be an example of men using religion for their personal gain. We can see these two factors at work in the diary of Lucinda Parsons, who spent the winter of 1850-1851 in Salt Lake. According to her, “these demons [polygamous men] marry some girls at 10 years of age. For instance a man will take a mother & her daughters & marry them all at one time & perhaps he has persuaded her to leave a husband with whome she has always lived happy, or be damned. She believes it for perhaps he is one of the heads of the church & in this way many respectable families have been ruined.” While these accusations are untrue, (Mormon men did not marry minors, nor were wives forced to leave their husbands) Lucinda does show how many perceived plural marriage.
The Mormons occasionally were made the subject of comedic plays and sketches.
After traveling through Utah, humorist Artemus Ward wrote A Visit to Brigham Young, a broadly comedic account of his visit. When Ward asks if Young is married, he replies, “I hev eighty wives, Mister Ward. I sertinly am married.” Ward then asks if Young likes his is marital setup, “He sed, ‘middlin.’” According to Ward, there is even a designated room for Young’s wives to fight in, “accordin to the rules of the London prize ring.” Brigham himself is portrayed as continually henpecked, with “many a horrible scar upon his body, inflicted with mop-handles, broom-sticks, and sich.” Ward’s description of poor Young, constantly overwhelmed by the demands of his wives, is a work of very broad humor.
Mark Twain also used polygamy for the punch line of a joke. When he visited Utah, he intended to help the women out of the shackles of polygamy. However, when Twain saw “these poor, ungainly, and pathetically ‘homely’” he concluded that “the man that marries one of them has done an act of Christian charity which entitles him to the kindly applause of mankind, not their harsh censure—and the man that maries sixty of them has done a deed of open-handed generosity so sublime that the nations should stand uncovered in his presence and worship in silence.” 
Regardless of the reaction, no one who visited the Mormons was unaffected by seeing polygamy.
-  Katherine M. Daynes, More Wives than One: The Transformation of the Mormon Marriage System, 1840-1910 (Urbana: University of Illinois Press, 2001), 98-101.
-  Mark Twain, Roughing It (Avon, Connecticut: The Heritage Press, 1972), 75.
-  Ibid, 30.
-  Lucena Parsons, “An Overland Honeymoon: Lucena Parsons,” Covered Wagon Women: 1840-1890 vol. II ed. Kenneth L. Holmes (Glendale, California: Arthur H. Clark, 1983, 273-274.
-  Artemus Ward, The Complete Works of Artemus Ward (New York: A.L. Burt Company, 1898), 64-66.
-  Mark Twain, Roughing It (Avon, Connecticut: The Heritage Press, 1972), 75